It has been argued theoretically that space is created by the integration of successive events over time. Unfortunately, past investigations into the development of spatial cognition have largely ignored possible relationships between time and space. There is some empirical evidence, however, which suggests that travel time will affect distance estimations (i.e., the extent of travelled space). In the present proposal, children and adults will be tested in large-scale environments, and will view films of simulated walks through these environments. In the first six experiments the actual time taken to traverse various distances will be manipulated. Subjects will walk through a linear array of objects (Experiment 1) and view a film of the same walk (Experiment 2). The findings of the first two experiments will be expanded by further manipulating the time taken to traverse locations, and varying the distances between these locations (Experiment 3). Experiment 4 will examine intentional and incidental memory for time and distance using the same paradigm. The time-distance relationship and the viability of the film simulation technique will be further examined when subjects encounter a filmed walk through an actual city street (Experiment 5) and a walk through a nonlinear spatial array (Experiment 6). In the last six experiments different aspects of the environment will be manipulated. It is expected that these manipulations will influence perceived time, which will in turn influence estimated distance. These manipulations will include: the number of objects between target locations (Experiment 7), the number of segments or divisions between target locations (Experiment 8), familiar and unfamiliar environments (Experiment 9), interesting and uninteresting walks (Experiment 10), in direct and direct routes (Experiment 11), and walks requiring a great deal of motor activity or minimal motor activity (Experiment 12).